When a media playlist builder is constructed to use unknown tags (MediaPlaylist.Builder().withUnknownTags(...)) the unknown tags will not be written using the ExtendedM3uWriter.
This commit enables the EXT_UNKNOWN_HANDLER and fixes a potential NullPointerException.
When a media playlist builder is constructed to use unknown tags (MediaPlaylist.Builder().withUnknownTags(...)) the unknown tags will not be written using the ExtendedM3uWriter. This commit enables the EXT_UNKNOWN_HANDLER and fixes a potential NullPointerException.